PIC PIC Pavement Distress & Failure Analysis 1 — Questions and Answers
Question 1: Which type of pavement distress is characterized by an interconnected series of cracks forming a pattern resembling an alligator's skin?
- Longitudinal cracking
- Alligator (fatigue) cracking (Correct answer)
- Transverse cracking
- Block cracking
Correct answer: Alligator (fatigue) cracking
Alligator or fatigue cracking forms an interconnected crack pattern resembling an alligator hide and indicates structural failure from repeated traffic loading.
Question 2: Rutting in an asphalt pavement is best described as:
- Cracking along the centerline of the roadway
- Permanent surface deformation in the wheel paths (Correct answer)
- Upward displacement of pavement at the edges
- Longitudinal separations between pavement layers
Correct answer: Permanent surface deformation in the wheel paths
Rutting is permanent deformation appearing as longitudinal depressions in the wheel paths caused by consolidation or lateral movement under traffic loads.
Question 3: Bleeding (or flushing) on an asphalt surface is caused by:
- Insufficient asphalt binder in the mix
- Excess asphalt binder migrating to the surface (Correct answer)
- Aggregate particles raveling from the surface
- Water infiltrating through surface cracks
Correct answer: Excess asphalt binder migrating to the surface
Bleeding occurs when excess asphalt binder migrates to the pavement surface, creating a shiny, sticky film that reduces skid resistance.
Question 4: Raveling in asphalt pavement refers to:
- Progressive loss of aggregate particles from the pavement surface (Correct answer)
- Formation of wheel-path depressions under traffic
- Upward curling of pavement edges due to moisture
- Cracking along lane or shoulder edges
Correct answer: Progressive loss of aggregate particles from the pavement surface
Raveling is the progressive disintegration of an asphalt surface through the loss of aggregate particles, often caused by inadequate compaction or aged binder.
Question 5: A paving inspector notices transverse cracks spaced evenly across a pavement. This pattern is most commonly associated with:
- Overloading by heavy trucks
- Thermal contraction of the asphalt layer (Correct answer)
- Excess moisture in the base course
- Improper roller operation during compaction
Correct answer: Thermal contraction of the asphalt layer
Transverse cracks spaced at regular intervals are typically caused by thermal contraction of the asphalt binder during temperature drops.
Question 6: Shoving in an asphalt pavement is a form of distress where:
- The surface aggregate wears smooth from traffic polishing
- The pavement surface has a corrugated or rippled appearance (Correct answer)
- Water seeps upward through the pavement base
- Reflective cracks appear above an underlying layer
Correct answer: The pavement surface has a corrugated or rippled appearance
Shoving produces a corrugated or rippled surface caused by instability in the asphalt mix, often at intersections or steep grades where braking and acceleration occur.
PIC PIC Pavement Distress & Failure Analysis 1
Which type of pavement distress is characterized by an interconnected series of cracks forming a pattern resembling an alligator's skin?